The present invention relates to a method of manufacturing semiconductor devices comprising MOS-type transistors and integrated circuits exhibiting improved quality, e.g., improved channel carrier mobility, high transistor drive current and improved circuit performance. The present invention is particularly applicable in fabricating high density integration semiconductor devices with a design rule less than 0.12 micron.
The escalating requirements for high density and performance associated with ultralarge-scale integration (ULSI) semiconductor devices require a design rule of about 0.12 micron and below, increased transistor and circuit speeds, high reliability and quality, and increased manufacturing throughput for economic competitiveness. The reduction of design rules to 0.12 micron and below challenges the limitations of conventional semiconductor manufacturing techniques.
High performance microprocessor applications require rapid speed of semiconductor circuitry. A limitation on the drive current of a transistor stems from reduced carrier mobility, i.e., electron or hole mobility, in the channel region of a MOSFET. The reduction of channel carrier mobility reduces the drive current and performance of the circuit.
Accordingly, there exists a need for efficient, cost-effective methodology enabling the fabrication of MOS devices exhibiting improved transistor drive current and circuit performance and high gate dielectric reliability. There exists a particular need for such methodology for fabricating semiconductor devices having a design rule of about 0.12 micron and under which is compatible with conventional process flow for improved efficiency and increased manufacturing throughput.
An advantage of the present invention is an improved method of fabricating semiconductor devices which exhibit increased channel carrier mobility, improved transistor drive current, improved circuit performance and improved gate dielectric reliability.
Additional advantages and other features of the present invention will be set forth in the description that follows and in part will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from the practice of the present invention. The advantages of the present invention may be realized and obtained as particularly pointed out in the appended claims.
According to an aspect of the present invention, the foregoing and other advantages are achieved in part by a method of manufacturing a semiconductor device, the method comprising: forming a gate oxide layer on an upper surface of a semiconductor substrate, the gate oxide layer having an upper surface with surface imperfections; and treating the upper surface of the gate oxide layer with an oxygen-containing plasma to reduce the surface imperfections.
Embodiments of the present invention comprise thermally oxidizing the upper surface of a silicon-containing semiconductor substrate to form the gate oxide layer having surface imperfections, such as an average surface roughness (Ar) of 2 xc3x85 or greater, and then treating the upper surface with the oxygen-containing plasma to reduce the surface imperfections resulting in a plasma treated gate oxide layer having an upper surface with an average surface roughness less than 1 xc3x85. Subsequent processing is conducted in a conventional manner to form a gate electrode and source/drain regions, thereby completing the MOSFET.
Additional advantages and aspects of the present invention will become readily apparent to those skilled in the art from the following detailed description, wherein only the preferred embodiment of the present invention is shown and described, simply by way of illustration of the best mode contemplated for carrying out the present invention. As will be described, the present invention is capable of other and different embodiments, and its several details are susceptible of modification in various obvious respects, all without departing from the spirit of the present invention. Accordingly, the drawing and description art to be regarded as illustrative in nature, and not as restrictive.